TWSBI Eco Fountain Pen - Cosmo - Onyx Trim

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A Radiant Twist on a Beloved Everyday Writer

The TWSBI Eco Cosmo elevates the classic Eco silhouette with a playful, luminous charm. Its crystal-clear resin barrel beautifully showcases your ink as it moves, while the Cosmo blue cap and finial softly glow to create a subtle cosmic effect in low light. Paired with a sleek onyx trim and a smooth-performing steel nib, this pen blends durability, style, and everyday practicality in one thoughtful design.

The piston-filling mechanism offers impressive ink capacity, and the inner-cap seal keeps the nib ready whenever inspiration strikes—ensuring clean, consistent writing from start to finish.

Product Features of TWSBI Eco Fountain Pen - Cosmo -  Onyx Trim:

• Transparent resin demonstrator body

• Cosmo glow cap + finial for a luminous accent

• Onyx-black trim and black-plated steel nib

• Piston-filling system with generous 1.76ml capacity

• Screw-cap with inner seal to prevent ink dry-out

• Available nib sizes: EF, F, M, B, 1.1 Stub

• Lightweight, comfortable resin grip

• Postable design for balanced writing

• Includes wrench & silicone grease for long-term care

Why Choose this TWSBI Eco Fountain Pen - Cosmo -  Onyx Trim?

The ECO Cosmo combines affordability with premium performance—ideal for beginners building their first collection and enthusiasts who appreciate reliability with a touch of fun. Its glow elements make it unique, while the transparent barrel and piston system offer a hands-on, immersive fountain pen experience.

Due to the nature of the material, there will be some variation in the pattern seen here. We cannot honor special requests.